Contrasting patterns of sequence divergence and base composition between Drosophila introns and intergenic regions.
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ABSTRACT:
SUBMITTER: Ometto L
PROVIDER: S-EPMC1833996 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND: Sequence periodicity with a period close to the DNA helical repeat is a very basic genomic property. This genomic feature was demonstrated for many prokaryotic genomes. The Escherichia coli sequences display the period close to 11 base pairs. RESULTS: Here we demonstrate that practically only ApA/TpT dinucleotides contribute to overall dinucleotide periodicity in Escherichia coli. The noncoding sequences reveal this periodicity much more prominently compared to protein-coding sequences. The sequence periodicity of ApC/GpT, ApT and GpC dinucleotides along the Escherichia coli K-12 is found to be located as well mainly within the intergenic regions. CONCLUSIONS: The observed concentration of the dinucleotide sequence periodicity in the intergenic regions of E. coli suggests that the periodicity is a typical property of prokaryotic intergenic regions. We suppose that this preferential distribution of dinucleotide periodicity serves many biological functions; first of all, the regulation of transcription.
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Project description:We compared gene expression differences in the polytypic species complex Mus musculus (Mus musculus musculus, Mus musculus domesticus, Mus musculus castaneus and Mus musculus ssp) with that of Mus spretus via oligonucleotide microarrays representing more than 20,000 genes. Analysis of the results by two way ANOVA statistics suggests that the most genes with significant differences in expression levels among the subspecies are found in liver and kidney and the least in testis. This picture is different when one compares with Mus spretus, where the largest number of differences is found in testis. Keywords: multi-species comparison
2006-12-13 | GSE2597 | GEO